Indiana Rep. Steve Buyer is taking an indefinite leave of absence from his job as a lawmaker to report for active military duty.

A Gulf War veteran and an Army reservist since 1987, Lt. Col. Buyer, a Republican, will act as an operational law judge advocate.

"A need was identified, of which congressman Buyer has the unique skill and experience to meet the requirements within the theater of operation," spokeswoman Laura Zuckerman said Thursday.

Buyer asked for an immediate indefinite leave of absence from House Speaker Dennis Hastert, who granted the request.

Buyer received a standing ovation from his colleagues, who were debating on the House floor late into the night to pass a resolution supporting troops fighting in and around Iraq.

Elected to Congress in 1992, Buyer served as a legal adviser at a prisoner-of-war camp in the Persian Gulf in 1990.

Three other House members are in the reserves and one is in the National Guard. One senator, Lindsey Graham, R-S.C., is in the reserves.

Members of Congress who are in the reserves are put on standby when they take their oath of office -- normally keeping them from being activated. However, call-up decisions are handled case by case.